Shutdown of North Atlantic Current Unlikely

You remember how in The Day After Tomorrow global warming leads to a shutdown of the Gulf Stream and catastrophic cooling of Europe. (This would be before the scene where the cold chases the kid down the hallway of the New York Public Library.) Well, just in case you didn't know, that isn't going to happen:

The idea, which held climate theorists in its icy grip for years, was that the North Atlantic Current, an extension of the Gulf Stream that cuts northeast across the Atlantic Ocean to bathe the high latitudes of Europe with warmish equatorial water, could shut down in a greenhouse world.

Without that warm-water current, Americans on the Eastern Seaboard would most likely feel a chill, but the suffering would be greater in Europe, where major cities lie far to the north. Britain, northern France, the Low Countries, Denmark and Norway could in theory take on Arctic aspects that only a Greenlander could love, even as the rest of the world sweltered.

All that has now been removed from the forecast. Not only is northern Europe warming, but every major climate model produced by scientists worldwide in recent years has also shown that the warming will almost certainly continue.

"The concern had previously been that we were close to a threshold where the Atlantic circulation system would stop," said Susan Solomon, a senior scientist at the National Oceanic and Atmospheric Administration. "We now believe we are much farther from that threshold, thanks to improved modeling and ocean measurements. The Gulf Stream and the North Atlantic Current are more stable than previously thought."

After consulting 23 climate models, the United Nations Intergovernmental Panel on Climate Change said in February it was "very unlikely" that the crucial flow of warm water to Europe would stall in this century. The panel did say that the gradual melting of the Greenland ice sheet along with increased precipitation in the far north were likely to weaken the North Atlantic Current by 25 percent through 2100. But the panel added that any cooling effect in Europe would be overwhelmed by a general warming of the atmosphere, a warming that the panel said was under way as a result of rising concentrations of carbon dioxide and other heat-trapping gases.

"The bottom line is that the atmosphere is warming up so much that a slowdown of the North Atlantic Current will never be able to cool Europe," said Helge Drange, a professor at the Nansen Environmental and Remote Sensing Center in Bergen, Norway.

I merely mention it because it is also an idea that Al Gore also suggests is possible in An Inconvenient Truth. Skirting the issue of the other claims made in that film, I was always a little skeptical of that one.

I also mention it because things like this get a life of their own. People exaggerate trends a little, the news media picks it up, and suddenly the entirety of Germany starts buying extra parkas.

Anyway, if you would like to know more about the science, Real Climate had a post on the issue a while ago.

Just remember: Europe no cooly.